Explanation:

In a passive sentence, the person or thing doing the action (the actor) is usually preceded by the word "by."Here in the sentence it is mentioned that every person should obey the traffic regulations which means that it is being said or advised.It is not saying stating any obvious thing.Also the sentence clearly states that the traffic regulations must be followed all times irrespective the tense.In the sentence 'should' is a modal verb and it is used with an ordinary verb.Hence we can coclude that option 2 is the correct answer.